The invention is based on an insert tool.
There are known insert tools for grinders, which have a grinding blade and a supporting disk made of rubber as a support for the grinding blade. The supporting disk and the grinding blade are placed with their hubs, which each have an essentially round opening in the middle, onto a drive shaft whose free end has a thread formed onto it. A nut that can be screwed onto the thread can clamp the grinding blade against the supporting disk and clamp the supporting disk against a flange connected to the drive shaft. When mounted, this produces a positive engagement in the axial direction and a frictional engagement in the circumference direction between the grinding blade, the supporting disk, and the flange.
The invention is based on an insert tool with a grinding blade and a supporting disk as well as a hub, which has at least one opening that can be used to clamp the hub to a driver flange of a grinder, which flange is connected to a drive shaft.
The invention proposes that the hub be comprised of a component that is separate from the supporting disk. This permits a particularly inexpensive and easily stackable insert tool to be produced, whose hub can easily be designed for a conventional driver device of a grinder with a nut and/or can be designed for a quick clamping system.
In an advantageous embodiment of the invention, the insert tool can be operatively connected to a driver device of the grinder by means of at least one detent element, which is supported so that it can move in opposition to a spring element and which engages in detent fashion in an operating position of the insert tool and fixes the insert tool in a positively engaging manner. The positive engagement permits a high degree of safety to be achieved and permits a simple, inexpensive, tool-free quick clamping system to be produced. The insert tool can be reliably prevented from unintentionally coming loose, even in braked drive shafts in which high braking moments can occur.
The movably supported detent element can permit a large deflection of the detent element during installation of the insert tool, which on the one hand, allows for a large overlap between two corresponding detent elements and a particularly reliable positive engagement and on the other hand, can produce an easily audible detent engagement noise, which advantageously informs an operator that a desired detent engagement has been achieved.
The detent element can fix the insert tool in a positively engaging manner directly or indirectly by means of an additional component, for example by means of a detent lever, plunger, or the like, which is coupled to the detent element and is supported in a rotating and/or axially movable fashion. Through positive engagement, the detent element can directly and/or indirectly fix the insert tool in various directions, such as in the radial direction, the axial direction, and/or particularly advantageously, in the circumference direction. It is also possible that the positively engaging fixing of the insert tool by means of the detent element in a first direction, for example in the radial direction, causes the insert tool to be fixed in a positively engaging manner in a second direction, for example in the circumference direction, by a component that is separate from the detent element.
If the hub has at least one first opening let into it for producing a positively engaging attachment to the driver device in at least one circumference direction and has at least one second opening let into it, which is separate from the first opening and is for producing a positively engaging attachment in the axial direction, then simple and inexpensive hubs can be produced, which can be advantageously embodied as essentially flat and without hooks. This can prevent the hubs from getting caught on one another during manufacture and storage, and permits a favorable handling of the insert tool by means of its hub. In addition, the components for fastening the hub can be designed advantageously for their function, i.e. either for fixing in the circumference direction or for fixing in the axial direction.
The hubs can advantageously be simply designed, with a closed centering bore, and a low-vibration operation of the insert tool can be achieved. In addition, a suitable choice of the diameter of the centering bore can permit the insert tools according to the invention to be fastened to conventional grinders using previously known fastening devices, in particular using fastening devices in which a clamping nut and a clamping flange can be used to fix the insert tool against a support surface on the drive shaft, with positive engagement in the axial direction and with frictional engagement in the circumference direction.
Another embodiment of the invention proposes that the hub have at least one oblong hole let into it, which has a wide region and at least one narrow region. The hub can be easily clamped in the axial direction by means of the oblong hole. In this connection, the hub can be used as a spring element, for example, in that the hub is elastically deformed while the component is being slid in the oblong hole. In addition, the hub can be used to deflect a component in the axial direction in opposition to a spring element. This permits savings with regard to additional components, installation work, and costs.
The invention also proposes that the hub have a contour, in particular an outer contour, that deviates from a rotationally symmetrical form, which can be attached in a positively engaging manner in the circumference direction to a corresponding contour, in particular an inner contour, of the supporting disk. A torque can advantageously be transmitted from the hub to the supporting disk by means of a positive engagement. Additional fastening elements, for example for producing a frictional engagement, can be avoided or at least assisted in their function, and costs can be reduced. The hub can be fastened directly to the driver flange, which permits a particularly exact positioning of the hub, the grinding blade, and the supporting disk in relation to one another. In addition, short detent elements can reach through the hub and secure it. The hub can have various contours deemed appropriate by one skilled in the art in order to transmit the torque by means of positive engagement, for example an oval or polygonal contour, etc., which can be formed onto various regions of the hub.
Another embodiment of the invention proposes that the contour, which deviates from a rotationally symmetrical form, be formed onto a shaped part of the hub that points in the axial direction, which permits a large transmitting surface to be produced between the hub and the supporting disk and therefore achieves an advantageously low surface pressure when transmitting a torque by means of the transmitting surface.
If the shaped part has inclined side walls, then the hub can be stacked in a particularly advantageous manner and the hub can be centered in the supporting disk.
The hub can be comprised of various materials deemed appropriate by one skilled in the art, for example a high-impact plastic, etc. However, it is advantageous if the hub is comprised of a deep-drawn sheet metal part, which makes it particularly inexpensive and easy to produce.
In the installed position, if a support surface of the hub and a support surface of the supporting disk are disposed in a common plane in the axial direction toward the grinder, then a corresponding support surface of a flange can be used jointly for both the supporting disk and the hub, and a common reference plane can be achieved. This saves on additional components and advantageously permits the achievement of a precise association of the supporting disk and the hub in relation to each other.
Another embodiment of the invention proposes that the hub be comprised of a component that is separate from the grinding blade, which permits an inexpensive manufacture, a space-saving storage, and a particularly simple reuse of the sheet metal hub.
If the hub, in the region in which it abuts the grinding blade, has a contour, which deviates from a rotationally symmetrical form and can be attached to a corresponding contour of the grinding blade in a positively engaging manner in the circumference direction, then the contours can be used to advantageously transmit a torque in a positively engaging manner. Additional fastening elements for transmitting a torque from the hub to the grinding blade can be assisted in their function or possibly be completely replaced. Basically, however, the hub can be attached to the grinding blade by means of any frictionally engaging, positively engaging, and/or materially adhesive connection deemed appropriate by one skilled in the art, for example a glued connection, riveted connection, clamped connection, etc.
If the hub has claws that can dig into the grinding blade, then the hub can be attached to the grinding blade in a simple, reliable, tool-free manner. A small axial force between the hub and the grinding blade permits powerful holding forces to be produced in the circumference direction. The axial force can advantageously be produced in the process of mounting the insert tool onto the grinder.
The claws can be comprised of additional components fastened to the hub. However, it is advantageous for the claws to be formed onto the hub, for example by means of a punching process. The production of the claws, therefore, can be advantageously integrated into the manufacturing process of the hub and additional components are not required.